SINGAPORE — At an island resort secluded from throngs of international reporters, a top aide to North Korean leader Kim Jong Un met with his American counterpart Wednesday to plan one of the most widely anticipated diplomatic events in a decade.

The meeting in Singapore — one of three bilateral meetings this week aimed at salvaging a summit between Kim and President Trump — dealt purely with logistics but has been shrouded in secrecy.

Hotel security guards blocked journalists from the premises of the resort off Singapore’s southeastern coast, and the White House and the State Department declined to confirm even mundane details, such as meeting dates or participants.

The logistics meeting came amid fresh doubts that Kim and Trump will actually sit down to negotiate the U.S. demand for the complete dismantlement of Pyongyang’s nuclear program. Last week, Trump canceled the summit, which had been scheduled for June 12 in Singapore, but days later approved a flurry of new talks in New York, Singapore and the Korean demilitarized zone to explore putting it back on. But on Wednesday, a top South Korean official warned that “significant” differences remain between the two sides on how to achieve denuclearization.

The two teams in Singapore are tasked with working out the logistics of the summit, including venue spaces, transportation, security and group photographs. They face a daunting target date of June 12 and the knowledge that a failed meeting could increase the chances for military confrontation between Washington and Pyongyang.

“We must remember that modern-day summits between two nations are completely scripted affairs — no detail, agenda item or deliverable is left to chance,” said Harry Kazianis, an Asia expert at the Center for the National Interest. “These take months to negotiate, and considering the stakes for North Korea and the United States, the outcome must be determined before the meeting.”

People watch a TV screen showing footage of President Trump and North Korean leader Kim Jong Un during a news program at the Seoul Railway Station on May 26. (Lee Jin-Man/AP)

Kim has expressed an unusual degree of interest in the summit’s logistics, asking Secretary of State Mike Pompeo during his visit to Pyongyang this month about fuel for the 6,000-mile round-trip flight to Singapore and how many bodyguards he could bring, according to people familiar with the conversations who requested anonymity because they were not authorized to discuss sensitive conversations.

Although most logistics teams would be led by a low-level bureaucrat, Kim sent his de facto chief of staff, Kim Chang Son, one of the country’s most powerful officials, to head the North Korean team. The U.S. team is led by White House Deputy Chief of Staff Joe Hagin, who has served in every Republican administration since Ronald Reagan’s.

On Wednesday afternoon, the two teams met at the luxurious Capella hotel on the island of Sentosa. Some members of the U.S. and North Korean teams dressed in khakis and short-sleeve button-down shirts in Singapore’s muggy 85-degree heat. The hotel has barred journalists from entering, and a Washington Post reporter was ordered to leave the property after speaking briefly to the American delegation.

As Hagin entered a meeting with Kim Chang Son, he told The Post that the teams were still discussing the venue for the summit. “We’re working at it,” he said.

This undated photo distributed on Sept. 3, 2017, by the North Korean government shows North Korean leader Kim Jong Un conducting an inspection at an undisclosed location. (Korean Central News Agency/Korea News Service/AP)

The organizers have plenty of options.

The Shangri-La, a 747-room hotel, has held major security conferences for years, including the annual Shangri-La Dialogue, which attracts dozens of ministers of defense and state, including top U.S. officials.

The Marina Bay Sands hotel and casino, a massive three-towered property with a giant swimming pool atop it, could appeal to Trump’s Las Vegas-style sensibilities but also poses a conflict of interest. The resort is owned by a company chaired by Sheldon Adelson, one of Trump’s biggest political donors, a prospect that could make it more or less appealing.

“Do you help your largest donor or avoid the swamp effect of doing so?” said Douglas Paal, an Asia expert at the Carnegie Endowment for International Peace.

Singapore, as a destination for the summit, has benefits and drawbacks. The island is considered neutral because it has long-standing trade and investment ties with the United States and has sustained a diplomatic relationship with North Korea since 1975, while other countries have severed ties. But it won’t offer the type of familiarity that benefited the meeting last month between South Korean President Moon Jae-in and Kim on the countries’ border.

“The South Koreans literally did a dress rehearsal for April 27 at Panmunjom together with North Korean officials a couple of days prior to the event, but that is presumably not an option in Singapore, so there is a lot of stage direction and protocol that will have to be worked through to satisfy both sides,” said Scott Snyder, an Asia expert at the Council on Foreign Relations. “They will have to agree on a minute-by-minute ticktock outlining the course of the entire encounter, including security, media and logistics.”

In advance of the summit, foreign journalists have flocked to Singapore to track every aspect of the planning. On Monday, when white men in suits began walking around the Shangri-La Hotel, South Korea’s Yonhap News Agency speculated in a story that the “Western-style” men could be the American team surveying a potential summit location, although such sightings are hardly rare in an international city such as Singapore.

Seungjin Ryu, a journalist with South Korea’s Channel A, said he spent six hours in the hot weather Tuesday, without a toilet or food break, waiting for a glimpse of the North Korean delegation outside the Fullerton Hotel.

“We gave up around 1 a.m. and got McDonald’s,” he said. “This has been tiring and confusing because of the lack of clear information from the two delegations.”

Meanwhile, a separate team of U.S. and North Korean negotiators in the Korean demilitarized zone appears to have hit obstacles following a four-hour meeting Wednesday. That group is focused on the substance of the negotiations should a Trump-Kim summit happen, but South Korean Unification Minister Cho Myoung-gyon said the different positions of Washington and Pyongyang “remain quite significant.”

“It will not be easy to narrow the gap and find common ground, but I think it would not be impossible,” he said during an address in Seoul.

The discussions resumed when Pompeo met with North Korean official Kim Yong Chol for dinner in New York on Wednesday.

Both levels of negotiations between U.S. and North Korean officials are aimed at closing the gap on the issue of North Korea’s nuclear weapons program ahead of the potential summit.

Cho said he remains hopeful for the meeting between Pompeo and Kim Yong Chol.

“Now that the leaders of the two countries are engaging in talks in a top-down manner, I think the chances are high that common ground can be found,” he said.